1. Field of the Invention
The present invention generally relates to testing fiber optic components and, more particularly, to a fiber optic component testing method and apparatus which provide visual information indicative of optical loss and continuity of a fiber optic component to technicians in a safe and protective environment. The present invention will permit the normal access and use by human activities using Network standards when working with potentially harmful light transmission sources.
2. Background Art
Technicians test fiber optic components (i.e., optical facilities) when placing the fiber optic components in given locations in order to ensure that the fiber optic components are functioning properly. Fiber optic components include fiber optic strands, jumpers, and cables. One way in which a technician tests a fiber optic component such as a fiber optic cable is by affixing an optical transmitter on the first end of the fiber optic cable. The technician then points the second end of the fiber optic cable towards a light reflectant object such as a piece of paper, the technician's hand, etc. The optical transmitter emits a signal of visible light into the first end of the fiber optic cable when the technician turns on the optical transmitter. The second end of the fiber optic cable emits the (attenuated) visible light after the visible light travels from the first end through the fiber optic cable. The visible light emitted from the second end of the fiber optic cable illuminates the paper, the technician's hand, etc., such that the technician is able to see the visible light emitted from the second end of the fiber optic cable. The technician then determines that the fiber optic cable is functioning properly upon seeing the visible light emitted from the second end of the fiber optic cable. That is, the technician determines that the fiber optic cable is functioning properly if the technician sees visible light emitted out from the second end of the fiber optic cable when the optical transmitter emits visible light into the first end of the fiber optic cable.
This testing practice is dangerous because it teaches technicians to indirectly visually observe light signals emitted from fiber optic components. As a result, technicians may determine that it is proper to visually observe light signals emitted from fiber optic components by directly looking with their eyes into the ends of fiber optic components in which the light signals are being emitted. This testing practice is also dangerous because it teaches technicians to point fiber optic components towards their hands, clothing, etc., and then have the light signals emitted from the fiber optic components radiate their body, clothing, etc.
Because visual light falls into the visible spectrum (400–700 nm), this testing practice gives technicians the false impression that all optical signals emitted from fiber optic components are visible and can be seen. A problem with this false impression is that telecommunication fiber optic components nominally transmit non-visible light signals during normal use instead of in the visual light spectrum. Non-visible (i.e., invisible) light signals fall outside of the light spectrum (400–700 nm) visible to the naked eye and, as a result, cannot be seen by the naked eye. If a fiber optic component is lit with an invisible signal while being tested by a technician using the visible light optical transmitter, then the technician would likely mistake the invisible signal for the “absence of light” and directly or indirectly view the light signals emitted from the light emitting end of the fiber optic component. A technician viewing invisible light signals emitted from a lit fiber optic component may be subjected to undue harm. Similarly, a technician pointing the emitting end of a lit fiber optic component on the technician's body, clothing, etc., such that the invisible light signals irradiate the technician's body, clothing, etc. may also be subjected to undue harm, especially with the new power levels of services being transmitted today.